Jupiter, Saturn, Uranus, and Neptune are sometimes known as the jovian (Jupiter-like) planets because they are all gigantic compared with Earth. They have a gaseous nature. Jupiter and Saturn are usually referred to as gas giants. Uranus and Neptune are known as ice giants because of their positions far from the sun and their internal molecular composition. All four of these planets have rocky materials and iron in their cores. This diagram shows the approximate distance of the jovian planets from the sun.